The Yale certified range are designed to be installed ideally into a solid concrete floor or brick wall. Fixing to wood is generally not recommended, especially if the wood is relatively thin. However, if you have no other alternative it is certainly better than no fixing fixing at all. If you fix to the floor of the closet I would advise trying to secure through the closet and into the floor joist. The length of the bolts supplied are 60mm, but they are not designed for timber so would need to be replaced with heavy duty timber screws.
Tom W